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Table of Contents
  1. Why do we heat the mixture in DNA extraction?
  2. What is the purpose of a hot water bath in DNA extraction?
  3. How does temperature affect DNA extraction?
  4. Why is hot or cold water better for DNA extraction?
  5. At what temp does DNA degrade?
  6. At what temperature does DNA denature?
  7. Can DNA be destroyed by heat?
  8. Why is DNA heated to 95 degrees?
  9. What heat does to DNA?
  10. What gives DNA negative charge?
  11. What happens during annealing DNA?
  12. Is denaturation of DNA reversible?
  13. What is the difference between denaturation and renaturation?
  14. How can you improve DNA stability?
  15. Which factor is not responsible for denaturation of DNA?
  16. What are the factors that cause protein denaturation?
  17. What is meant by denaturation of DNA?
  18. Why denaturation of DNA is important?
  19. How does DNA denaturation and renaturation happen?
  20. What is PCR used for?
  21. What is denaturation and renaturation of DNA?
  22. Why does high pH denature DNA?
  23. What does formamide do to DNA?
  24. What is the purpose of DNA hybridization?
  25. What is the principle of hybridization?
  26. What is needed for DNA hybridization?
  27. What are DNA hybridization techniques?
  28. What are the applications of DNA sequencing?
  29. What are the applications of hybridization?
  30. What is the other name of hybrid DNA?
  31. What is the purpose of the warm water bath in DNA extraction?
  32. Why is frozen onion used in DNA extraction?
  33. Why is cold alcohol used in DNA extraction?
  34. Can you extract DNA from onion?
  35. Does an onion cell contain DNA?
  36. What type of DNA is found in an onion?
  37. How do you extract DNA from a banana?
  38. What is the best fruit to extract DNA from?
  39. Why do you mash the fruit before extracting DNA?
  40. What does the banana DNA looks like?
  41. Does any living thing not have DNA?
  42. Is human DNA the same as a banana?
  43. Does banana contain DNA?
  44. What has the closest DNA to humans?
  45. How related are all humans?
  46. How much of our DNA is junk?
  47. Is junk DNA really junk?
  48. What percentage of human DNA is viral?
  49. What percentage of human DNA is active?
  50. Do we only use 5% of our DNA?
  51. What percent of human DNA is exons?
  52. Does junk DNA have a purpose?
  53. Why is junk DNA considered junk?
  54. Are exons junk DNA?
  55. Are transposons junk DNA?
  56. What is the C paradox?
  57. Why are transposons called selfish DNA?
  58. What is highly repetitive DNA?

Why do we heat the mixture in DNA extraction?

Heating helps to denature proteins, extract DNA from spots, increase speed of chemical reactions, inactivate enzymatical reactions inhibitors etc. Heating is not an alternative method of DNA precipitation.

What is the purpose of a hot water bath in DNA extraction?

The hot water bath softens the cell walls and membranes, so the DNA is released. It also further denatures (deactivates) the enzymes in the mixture that can degrade DNA.

How does temperature affect DNA extraction?

Temperature has a significant effect on the amount of DNA that can be extracted: the lower the temperature, the greater the yield of DNA. Hence, whenever possible, specimens should be kept at cold temperatures, preferably frozen.

Why is hot or cold water better for DNA extraction?

Why is cold water better than warm water for extracting DNA? Cold water helps keep the DNA intact during the extraction process. A cell’s DNA is usually protected from such enzymes (called DNases) by the nuclear membrane, but adding detergent destroys that membrane.

At what temp does DNA degrade?

Conclusions. We found that under dry conditions, DNA degradation begins at 130°C, and continues in a linear manner until complete degradation occurs around 190°C.

At what temperature does DNA denature?

Heating. Theoretically the 86-bp DNA fragment will be completely denatured during the heating process at 95°C since the melting temperature (Tm) of the DNA was calculated to be 76.2°C according to Wallace et al. [15].

Can DNA be destroyed by heat?

There is little literature regarding the effect of fire and extreme heat on blood and the detection of blood. Blood and DNA are believed to be no longer traceable after exposure to a temperature of 1000 °C.

Why is DNA heated to 95 degrees?

4. Heat to 95 degrees. At this temperature the DNA will denature, splitting the double standed DNA by breaking thy hydrogen bonds holding the bases together. This results in two separate strands with exposed bases.

What heat does to DNA?

When a DNA solution is heated enough, the double-stranded DNA unwinds and the hydrogen bonds that hold the two strands together weaken and finally break. The process of breaking double-stranded DNA into single strands is known as DNA denaturation, or DNA denaturing.

What gives DNA negative charge?

The phosphate backbone of DNA is negatively charged due to the bonds created between the phosphorous atoms and the oxygen atoms. Each phosphate group contains one negatively charged oxygen atom, therefore the entire strand of DNA is negatively charged due to repeated phosphate groups.

What happens during annealing DNA?

Annealing – when the temperature is lowered to enable the DNA primers to attach to the template DNA. Extending – when the temperature is raised and the new strand of DNA is made by the Taq polymerase enzyme.

Is denaturation of DNA reversible?

The DNA denaturation process is reversible under controlled conditions of pH and ionic strength. If the temperature is slowly decreased in the solution where the DNA had been denatured, the DNA chains will spontaneously reanneal and the original double helix structure is restored.

What is the difference between denaturation and renaturation?

The main difference between denaturation and renaturation of DNA is that denaturation of DNA is the process of separating dsDNA into single strands. But, in contrast, renaturation of DNA is the process of forming base pairs; that is, coming back together of the complementary DNA strands.

How can you improve DNA stability?

DNA duplex stability therefore increases with increasing salt concentration. Divalent cations such as Mg2+ are more stabilizing than Na+ ions, and some metal ions bind to specific loci on the DNA duplex.

Which factor is not responsible for denaturation of DNA?

Which of this factor is not responsible for thermal denaturation of DNA? Explanation: When DNA duplex is laid open to the specific conditions like temperature, pH, or ionic strength it will interrupt the hydrogen bond between strands and they are no longer held together.

What are the factors that cause protein denaturation?

Changes in pH, Increased Temperature, Exposure to UV light/radiation (dissociation of H bonds), Protonation amino acid residues, High salt concentrations are the main factors that cause a protein to denature.

What is meant by denaturation of DNA?

DNA denaturation is the process of breaking down the DNA molecule, generally for the purposes of comparison or sequencing. As with many laboratory techniques, there are a variety of ways to denature DNA — and each of them tend to be better for specific applications.

Why denaturation of DNA is important?

When mixed, in suitable conditions, denatured DNA from two different organisms, may have segments with complementary sequences that can pair forming hybrid double hybrid helices (with DNA chains from each organism). Such DNA hybridization is useful to estimate the evolutionary proximity between two different species.

How does DNA denaturation and renaturation happen?

In the process of denaturation, an unwinding of DNA double-strand takes place, leading to two separate single strands on applying heat. Separate single strands rewind on cooling and the process is known as renaturation. Ans – Renaturation occurs when the denatured DNAs are cooled in suitable conditions.

What is PCR used for?

What is PCR? Sometimes called “molecular photocopying,” the polymerase chain reaction (PCR) is a fast and inexpensive technique used to “amplify” – copy – small segments of DNA.

What is denaturation and renaturation of DNA?

Denaturation causes a marked decrease in viscosity. If melted DNA is cooled it is possible to reassociate the separated strands, a process known as renaturation. However, a stable double-stranded molecule may be formed only if the complementary strands collide in such a way that their bases are paired precisely.

Why does high pH denature DNA?

At pH 9 or higher, DNA is susceptible to alkaline denaturation due to the abundance of hydroxide ions. These negatively-charged ions remove hydrogen ions from the base pairs of DNA, thereby breaking the hydrogen bonds between and causing the DNA strands to denature.

What does formamide do to DNA?

Formamide lowers melting temperatures (Tm) of DNAs linearly by 2.4-2.9 degrees C/mole of formamide (C(F)) depending on the (G+C) composition, helix conformation and state of hydration. The inherent cooperativity of melting is unaffected by the denaturant.

What is the purpose of DNA hybridization?

DNA hybridization provides an extremely powerful tool in molecular biology. Hybridization allows the identification and cloning of specific genes, analysis of levels of mRNA in cells, analysis of the copy number of sequences in the genome, and DNA fingerprinting, among other applications.

What is the principle of hybridization?

​Hybridization Hybridization is the process of combining two complementary single-stranded DNA or RNA molecules and allowing them to form a single double-stranded molecule through base pairing.

What is needed for DNA hybridization?

Hybridization of DNA is accomplished by heating strands of DNA from two different species to 86° C [186.8° F]. This breaks the hydrogen bonds between all complementary base pairs. The result is many single-stranded segments of DNA. The single-stranded DNA from both species is mixed together and allowed to slowly cool.

What are DNA hybridization techniques?

Hybridization methods

Method Target
Northern blot RNA fragments separated by gel electrophoresis
Slot/dot blot Total DNA or RNA
Colony blot DNA or RNA in microbial colonies
Fluorescent in situ hybridization (FISH) DNA or RNA in microbial cells

What are the applications of DNA sequencing?

Applications of DNA sequencing technologies Knowledge of the sequence of a DNA segment has many uses. First, it can be used to find genes, segments of DNA that code for a specific protein or phenotype. If a region of DNA has been sequenced, it can be screened for characteristic features of genes.

What are the applications of hybridization?

Current applications of the hybridization assays include the detection of a wide variety of infectious agents, the demonstration of human chromosomal aberrations, the detec- tion of many genes responsible for inherited diseases, and the illustration of gene rearrangement and oncogene amplification in many tumors.

What is the other name of hybrid DNA?

Heteroduplex

What is the purpose of the warm water bath in DNA extraction?

The hot water bath softens the cell walls and membranes, so the DNA is released. It also further denatures (deactivates) the enzymes in the mixture that can degrade DNA. More is not better, longer heating can denature the DNA.

Why is frozen onion used in DNA extraction?

The DNA that is isolated can be digested using various endonucleases, followed with an electrophoresis of the digest. We use an onion because of its’ cost, abundance and low starch content. The DNA is soluble in the detergent solution but is insoluble in the alcohol.

Why is cold alcohol used in DNA extraction?

Using ice-cold water and ice-cold alcohol will increase your yield of DNA. The cold water protects the DNA by slowing down enzymes that can break it apart. The cold alcohol helps the DNA precipitate (solidify and appear) more quickly.

Can you extract DNA from onion?

Answer: Chopping the onion allows its tissues to be broken up so that the meat tenderizer solution can take effect and attack the cell walls and membranes. To extract DNA, the nucleus must come out of the cell. In fact, there are nucleases inside cells that could attack and degrade DNA.

Does an onion cell contain DNA?

Every cell in our body has a master control region called the nucleus. Inside the nucleus, there is a material called deoxyribonucleic acid, or DNA. Onions have cells, too, and their cells each contain a nucleus with lots of DNA.

What type of DNA is found in an onion?

Since the onion (Allium cepa) is a diploid organism having a haploid genome size of 15.9 Gb, it has 4.9x as much DNA as does a human genome (3.2 Gb). Other species in the genus Allium vary hugely in DNA content without changing their ploidy.

How do you extract DNA from a banana?

  1. Put 1/2 cup of distilled water and one banana into the blender.
  2. Mix 1 teaspoon of soap with 1/4 teaspoon of salt in a plastic cup.
  3. Add 2 tablespoons of the banana mixture to the cup containing the soap solution.
  4. Insert a filter into a clean plastic cup so it does not touch the bottom of the cup.

What is the best fruit to extract DNA from?

Experiment to purify DNA from fruit Bananas, kiwis and strawberries all work well. (Remove the skin of the bananas and kiwi, we just want the insides!) Step 2: In a separate bowl, mix the washing up liquid, salt and tap water.

Why do you mash the fruit before extracting DNA?

Mashing the banana exposes a greater surface area from which to extract the DNA. The liquid soap is added to help break down cell membranes to release the DNA. The filtration step (pouring the mixture through the strainer) allows for the collection of the DNA and other cellular substances.

What does the banana DNA looks like?

It also controls many of the features that make an organism unique. DNA or deoxyribonucleic acid is found in all living things. Its natural shape is called a double helix and when seen under extremely high-powered microscopes, it looks kind of like a ladder twisted into a spiral shape.

Does any living thing not have DNA?

Based on this fact, almost all the biologists must think that there is no organism without DNA. However, it is possible that such an organism, especially a microorganism carrying RNA genome, exists on the Earth. First, about half of the viruses have an RNA genome, either single stranded or double stranded (Flint et al.

Is human DNA the same as a banana?

About 60 percent of our genes have a recognizable counterpart in the banana genome! “Of those 60 percent, the proteins encoded by them are roughly 40 percent identical when we compare the amino acid sequence of the human protein to its equivalent in the banana,” Brody adds.

Does banana contain DNA?

It holds a stringy substance called DNA, which is like a set of blueprints, or instructions. DNA contains a code for how to build a life-form and put together the features that make that organism unique. Just like us, banana plants have genes and DNA in their cells, and just like us, their DNA determines their traits.

What has the closest DNA to humans?

chimpanzees

According to calculations by geneticist Graham Coop of the University of California, Davis, you carry genes from fewer than half of your forebears from 11 generations back. Still, all the genes present in today’s human population can be traced to the people alive at the genetic isopoint.

How much of our DNA is junk?

Our genetic manual holds the instructions for the proteins that make up and power our bodies. But less than 2 percent of our DNA actually codes for them. The rest — 98.5 percent of DNA sequences — is so-called “junk DNA” that scientists long thought useless.

Is junk DNA really junk?

Only about 1 percent of DNA is made up of protein-coding genes; the other 99 percent is noncoding. Scientists once thought noncoding DNA was “junk,” with no known purpose. However, it is becoming clear that at least some of it is integral to the function of cells, particularly the control of gene activity.

What percentage of human DNA is viral?

The human genome contains billions of pieces of information and around 22,000 genes, but not all of it is, strictly speaking, human. Eight percent of our DNA consists of remnants of ancient viruses, and another 40 percent is made up of repetitive strings of genetic letters that is also thought to have a viral origin.

What percentage of human DNA is active?

In 2012, scientists with the ENCODE project, a huge catalog of all noncoding DNA in the human genome, declared that 80 percent of our DNA was active and performing some function. Now scientists at Oxford have analyzed the human genome and claim that less than 10 percent of our DNA is functional.

Do we only use 5% of our DNA?

A new study suggests that only 8.2 percent of human DNA, or about 250 million of these so-called DNA letters, are functional, and more than 2 billion are not. …

What percent of human DNA is exons?

For instance, in the human genome only 1.1% of the genome is spanned by exons, whereas 24% is in introns, with 75% of the genome being intergenic DNA.

Does junk DNA have a purpose?

What’s more, its repetitive nature is thought to make the genome less stable and more susceptible to damage or disease. Until fairly recently, scientists believed this so-called “junk” or “selfish” DNA did not serve any real purpose.

Why is junk DNA considered junk?

When there is much non-coding DNA, a large proportion appears to have no biological function, as predicted in the 1960s. Since that time, this non-functional portion has controversially been called “junk DNA”.

Are exons junk DNA?

For about 15 years, scientists have known that certain “junk” DNA — repetitive DNA segments previously thought to have no function — could evolve into exons, which are the building blocks for protein-coding genes in higher organisms like animals and plants. “Alu elements are a major source of new exons.

Are transposons junk DNA?

Transposable elements (TEs), also known as “jumping genes” or transposons, are sequences of DNA that move (or jump) from one location in the genome to another. Maize geneticist Barbara McClintock discovered TEs in the 1940s, and for decades thereafter, most scientists dismissed transposons as useless or “junk” DNA.

What is the C paradox?

The C value paradox is that the amount of DNA in a haploid genome (the 1C value) does not seem to correspond strongly to the complexity of an organism, and 1C values can be extremely variable. According to this hypothesis, the organism requires a certain amount of DNA, which could consist of any sequence.

Why are transposons called selfish DNA?

Transposable elements are often termed selfish DNA because they are parasitic DNA sequences that inhabit a host genome. Over time, many copies of selfish DNA are inactivated by mutations and deletions, leaving DNA remnants called junk DNA.

What is highly repetitive DNA?

Repetitive DNA: DNA sequences that are repeated in the genome. These sequences do not code for protein. One class termed highly repetitive DNA consists of short sequences, 5-100 nucleotides, repeated thousands of times in a single stretch and includes satellite DNA.